Method for treating emphysema with condensable thermal vapor

ABSTRACT

A method for treating emphysema with a condensable vapor includes creating a plurality of collateral channels through the airway walls, and delivering the condensable vapor to the airways. The condensable vapor flows to the diseased parenchymal tissue through the airways and the collateral channels. Condensable vapor to contact the tissue heats the tissue, reducing it in volume. Apparatuses are described to create the openings and ablate the lung tissue.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit and priority to provisional patentapplication No. 62/582,220, filed Nov. 6, 2017, and entitled “METHOD FORTREATING EMPHYSEMA WITH CONDENSABLE THERMAL VAPOR.”

BACKGROUND OF THE INVENTION

This invention relates to medical devices, systems and methods, and inparticular to intrabronchial catheters, systems and methods fordelivering a condensable vapor to diseased tissue in a patient's lungs.

Heating therapies are increasingly used in various medical disciplinesincluding pulmonology, cardiology, dermatology, orthopedics, oncology aswell as a number of other medical specialties. In general, the manifoldclinical effect of super physiological tissue temperatures results fromunderlying molecular and cellular responses, including expression ofheat-shock proteins, cell death, protein denaturation, tissuecoagulation and ablation. Associated with these heat-induced cellularalternations and responses are dramatic changes in tissue structure,function and properties that can be exploited for a desired therapeuticoutcome such as tissue injury, shrinkage, modification, destructionand/or removal.

Heating techniques in the lung pose several technical challenges becauselung tissue is more aerated than most tissues and also due to itsvascularization. Accordingly, these new heating methods, devices andsystems for rapid, controllable, effective and efficient heating of lungtissue are needed. The present invention is directed at meeting these aswell as other needs.

SUMMARY OF THE INVENTION

Methods for treating emphysema include reducing the lung volume of thediseased tissue, and fixing the diseased tissue while it is in thereduced state.

In embodiments, at least one collateral channel or opening is createdthrough the airway walls of a hyperinflated lung segment. Condensablevapor is delivered into the lung segment via the airway. The condensablevapor naturally traverses distally through the airways into theparenchyma. Additionally, some of the vapor traverses through the newlycreated openings into the parenchyma providing a second or ancillarymodality for diseased tissue ablation and lung volume reduction (LVR).

Without intending to be bound by theory, acutely and significantlyreducing the hyperinflated segments by creating openings through theairway walls and then delivering the condensable vapor is beneficialbecause the novel method remodels the treated lung by fixing the lungsegments in the reduced state through collagen strands that develop as aresult of diseased tissue replacement. Substantial volume reductionremains permanent despite the openings potentially closing over time.

Additionally, embodiments of the subject invention have severaladvantages over use of implants to carry out LVR. Particularly, becauseembodiments of the subject invention do not require implants, the numberof complications associated with LVR implants is reduced. Additionally,the surgically created openings serve to drain the lung segment duringthe above mentioned remodeling period and therefore reduce the risk ofpneumonia.

The quantity and the location of the openings to be created may varywidely. In embodiments, at least one opening is created in the airwaysdistal to where condensable vapor will be delivered to the airway. Thiscan have the advantage of maintaining the openings patent longercompared to other treatment modalities such as, for example, applyingdirect heat to the opening. Applying direct heat (e.g., resistive orRF-based heat) to the opening can undesirably increase cellproliferation leading to hole closure prior to the remodeling (perhaps a4 to 6-week process).

In embodiments, openings are created in each of the segmental airways inorder to reduce the overall hyperinflation of the lobe, and thencondensable vapor is applied to the most diseased segment(s).Determination of the most diseased segments may be performed by, e.g.,CT scan, and other diagnostic testing.

Condensable vapor can be applied proximally or distally to thesurgically created openings. In embodiments, the condensable vapor isdelivered from a vapor delivery catheter advanced into the airway to adesired location. In some embodiments, the vapor delivery catheter isadvanced through the surgically created openings and the condensablevapor is delivered beyond the airway walls and directly into the targettissue.

In other embodiments, vapor is delivered to the openings only and notwithin the airways. In one embodiment, vapor is delivered to theopenings-only via a balloon catheter. The balloon catheter includes twoinflatable members separated axially. The balloon catheter is advancedthrough the opening until the two inflatable members contain theopening. Vapor can be delivered from an egress aperture in the shaft ofthe catheter and into the space defined by the two balloons. Anadvantage of delivering vapor and treating the opening-only is that lessmucociliary transport disruption occurs compared to delivering vapor andtreating all of the airways. Additionally, the lack of disruption mayreduce the likelihood of pneumonia through better liquid clearance ofthe treated segment.

In other embodiments, a closure (e.g., an occlusion) is created along anairway in a hyperinflated segment by applying a concentration of vaporat the segmental airway using a dual balloon catheter.

The method of forming a closure or occlusion along the airway can beperformed in addition to any of the methods described herein. Indeed,all steps described herein may be combined in any logical manner andsequence except where such steps would exclude one another.

In one embodiment, for example, the method of forming an occlusion isfollowed by the step of creating one or more openings. The openings maybe created 4 to 6 weeks after the occlusion ablation. In otherembodiments, the openings are created more than 6 weeks from theocclusion ablation. Once the airway has been occluded (e.g., after 4 to6 weeks from the occlusion procedure), openings are made in the airwaysof the diseased segment to relieve the hyperinflated volume of thediseased segment. Optionally, vapor is applied through the surgicallycreated openings serving to remodel, seal and fix the lung segment inthe reduced state.

Still other descriptions, objects and advantages of the presentinvention will become apparent from the detailed description to follow,together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a human respiratory system;

FIG. 2 illustrates the airway in the respiratory system;

FIG. 3 illustrates one method of treating a volume of lung tissue inaccordance with the present invention;

FIG. 4 is a schematic illustrating one embodiment of a vapor generatorin accordance with the present invention;

FIG. 5 illustrates one embodiment of a generator display or userinterface;

FIG. 6 is a perspective view of one embodiment of an energy deliverycatheter in accordance with present invention;

FIG. 7 is a longitudinal cross-sectional view of yet another embodimentof a catheter in accordance with the present invention;

FIG. 7A transverse a cross-sectional view of the catheter of FIG. 7taken along lines 7A-7A;

FIG. 7B is a transverse cross-sectional view of catheter illustrated inFIG. 7 taken along lines 7B-7B;

FIG. 8 is an illustration depicting a plurality of collateral channelsinstalled along an airway and serving to release trapped air from thelung;

FIG. 9 is an illustration depicting a vapor delivery catheter deliveringvapor in an airway in the vicinity of a surgically created channel;

FIG. 10 is an illustration depicting a vapor delivery catheterdelivering vapor through a surgically created opening;

FIG. 11 is an illustration depicting a dual-balloon vapor deliverycatheter delivering vapor to only a surgically created opening; and

FIGS. 12-14 are illustrations of a piercing member, electrical ablationprobe, and dilator, respectively.

DETAILED DESCRIPTION OF THE INVENTION

Before the present invention is described in detail, it is to beunderstood that this invention is not limited to particular variationsset forth herein as various changes or modifications may be made to theinvention described and equivalents may be substituted without departingfrom the spirit and scope of the invention. As will be apparent to thoseof skill in the art upon reading this disclosure, each of the individualembodiments described and illustrated herein has discrete components andfeatures which may be readily separated from or combined with thefeatures of any of the other several embodiments without departing fromthe scope or spirit of the present invention. In addition, manymodifications may be made to adapt a particular situation, material,composition of matter, process, process act(s) or step(s) to theobjective(s), spirit or scope of the present invention. All suchmodifications are intended to be within the scope of the claims madeherein.

Methods recited herein may be carried out in any order of the recitedevents which is logically possible, as well as the recited order ofevents. Furthermore, where a range of values is provided, it isunderstood that every intervening value, between the upper and lowerlimit of that range and any other stated or intervening value in thatstated range is encompassed within the invention. Also, it iscontemplated that any optional feature of the inventive variationsdescribed may be set forth and claimed independently, or in combinationwith any one or more of the features described herein.

All existing subject matter mentioned herein (e.g., publications,patents, patent applications and hardware) is incorporated by referenceherein in its entirety except insofar as the subject matter may conflictwith that of the present invention (in which case what is present hereinshall prevail).

Reference to a singular item, includes the possibility that there areplural of the same items present. More specifically, as used herein andin the appended claims, the singular forms “a,” “an,” “said” and “the”include plural referents unless the context clearly dictates otherwise.It is further noted that the claims may be drafted to exclude anyoptional element. As such, this statement is intended to serve asantecedent basis for use of such exclusive terminology as “solely,”“only” and the like in connection with the recitation of claim elements,or use of a “negative” limitation.

FIG. 1 illustrates a human respiratory system 10. The respiratory system10 resides within the thorax 12 that occupies a space defined by thechest wall 14 and the diaphragm 16. The human respiratory system 10includes left lung lobes 44 and 46 and right lung lobes 48, 50, and 52.

The respiratory system 10 further includes trachea 18; left and rightmain stem bronchus 20 and 22 (primary, or first generation) and lobarbronchial branches 24, 26, 28, 30, and 32 (second generation). Segmentaland sub-segmental branches further bifurcate off the lobar bronchialbranches (third and fourth generation). Each bronchial branch andsub-branch communicates with a different portion of a lung lobe, eitherthe entire lung lobe or a portion thereof. As used herein, the term “airpassageway” or “airway” means a bronchial branch of any generation,including the bronchioles and terminal bronchioles.

FIG. 2 is a perspective view of the airway anatomy emphasizing the upperright lung lobe 48. In addition to the bronchial branches illustrated inFIG. 1, FIG. 2 shows sub-segmental bronchial branches (fourthgeneration) that provide air circulation (i.e. ventilation) to superiorright lung lobe 48. The bronchial segments branch into six generationsand the bronchioles branch into approximately another three to eightgenerations or orders. Each airway generation has a smaller diameterthan its predecessor, with the inside diameter of a generation varyingdepending on the particular bronchial branch, and further varyingbetween individuals. A typical lobar bronchus providing air circulationto the upper right upper lobe 48 has an internal diameter ofapproximately 1 cm. Typical segmental bronchi have internal diameter ofapproximately of about 4 to about 7 mm.

The airways of the lungs branch much like the roots of a tree andanatomically constitute an extensive network of air flow conduits thatreach all lung areas and tissues. The airways have extensive branchingthat distally communicates with the parenchyma alveoli where gasexchange occurs. Because of these physiological characteristics of theairways, a medium, such as a vapor, delivered through an airway can bedelivered focally or more regionally depending largely on the airwaylocation at which the medium is delivered or dispersed.

While not illustrated, a clear, thin, shiny covering, known as theserous coat or pleura, covers the lungs. The inner, visceral layer ofthe pleura is attached to the lungs and the outer parietal layer isattached to the chest wall 14. Both layers are held in place by a filmof pleural fluid in a manner similar to two glass microscope slides thatare wet and stuck together. Essentially, the pleural membrane aroundeach lung forms a continuous sac that encloses the lung and also forms alining for the thoracic cavity 12. The space between the pleuralmembranes forming the lining of the thoracic cavity 12 and the pleuralmembranes enclosing the lungs is referred to as the pleural cavity. Ifthe air tight seal around the lungs created by the pleural members arebreached (via a puncture, tear, or is otherwise damaged) air can enterthe sac and cause the lungs to collapse.

Bronchoscopy Approach

FIG. 3 illustrates a bronchoscopic procedure in accordance with someembodiments of the present invention. FIG. 3 shows a bronchoscope 100having a working channel into which an energy delivery catheter 200 (oranother tool) is inserted. Bronchoscope 100 is inserted into a patient'slungs while the proximal portion of the energy delivery catheter 200remains outside of the patient. Energy delivery catheter 200 is adaptedto operatively couple to an energy generator 300 as further discussedbelow. Examples of energy delivery catheters include, withoutlimitation, a condensable vapor ablation catheter as described herein.

Energy Generator

FIG. 4 is a schematic diagram of an energy generator 300 configured as avapor generator. In embodiments, vapor generator is configured todeliver a controlled dose of vapor to one or more target lung tissues.Vapor generator 300 is adapted to convert a biocompatible liquid 301(e.g. saline, sterile water or other biocompatible liquid), into a wetor dry vapor, which is then delivered to one or more target tissues. Awet vapor refers to a vapor that contains vaporous forms of the liquidas well as a non-negligible proportion of minute liquid droplets carriedover with and held in suspension in the vapor. A dry vapor refers to avapor that contains little or no liquid droplets. In general, vaporgenerator 300 is configured to have a liquid capacity between about 1000to 2500 cc and configured to generate a vapor having a pressure betweenabout 5-100 prig and temperatures between about 100-175° C.

In embodiments, vapor generator 300 is configured as a self-contained,medical-grade generator unit comprising at least a vaporizing unit 302,a vapor inlet 304, and a vapor outlet 306. The vaporizing unit 302comprises a fluid chamber for containing a fluid 301, preferably abiocompatible, sterile fluid, in a liquid state. In embodiments, vaporoutlet 306 is coupled to one or more pipes or tubes 314, which in turnare placed in fluid communication with an energy delivery catheter 200.Vapor flow from vapor generator 300 to a catheter (and specifically avapor lumen of said catheter) is depicted as a vapor flow circuit 314wherein flow of the vapor in circuit 314 is indicated by arrows 314 inFIG. 4. In a preferred embodiment, vapor generator is configured todeliver a repeatable dose of vapor to energy delivery catheter 200. Thedose of the vapor may vary. Exemplary doses range, without limitation,from 100 to 1000 calories.

Vaporizer unit 302 is configured to heat and vaporize a liquid containedtherein. Other components can be incorporated into the biocompatibleliquid 301 or mixed into the vapor. For example, these components can beused to control perioperative and/or post procedural pain, enhancetissue fibrosis, and/or control infection. Other constituents, for thepurpose of regulating vapor temperatures and thus control extent andspeed of tissue heating, can be incorporated; for example, in oneimplementation, carbon dioxide, helium, other noble gases can be mixedwith the vapor to decrease vapor temperatures.

Vaporizing unit 302 is also shown having a fluid inlet 304 to allowliquid 301 to be added to the fluid chamber as needed. Fluid chamber canbe configured to accommodate or vaporize sufficient liquid as needed toapply vapor to one or more target tissues. Liquid in vaporizing unit 302is heated and vaporized and the vapor flows into vapor outlet 306. Anumber of hollow tubular shafts or pipes 314 are adapted to fluidlyconnect vapor outlet 306 to the catheter 200.

In embodiments, a flexible hollow tube or umbilical-like cord extendsfrom the generator 300 and terminates in a handle (not shown). Thehandle is adapted to operatively couple to a variety of types of energydelivery catheters via a hub assembly (such as hub assembly 214 shown inFIG. 5 and discussed herein). In embodiments, the hub assembly or otherconnecting means is configured to allow for a secure, fluidly sealed,and quick release between the catheter and generator handle. Examples ofsuitable quick connect and release mechanisms include, withoutlimitation, Luer Lock hub assemblies and fittings.

In embodiments, a catheter and vapor generator are configured to bedirectly coupled to one another via mating connectors. Vapor delivery iscontrolled by the generator, a controller external to the generator, oractuating buttons and mechanisms on the catheter itself. For example,the catheter may comprise a handpiece portion to control vapor doses.

Preferably, there is little or no vapor-to-liquid transition duringmovement of the vapor through vapor flow circuit 314. Vapor flow throughvapor flow circuit 314 is unidirectional (in the direction of arrows314), accordingly one or more isolation valves 320 are incorporated invapor flow circuit 314. Isolation valves 320, which are normally openduring use of generator 300, serve to minimize vapor flow in a directionopposite that of the vapor flow circuit 314.

A priming line 330, branching from main vapor flow circuit 314, isprovided to minimize or prevent undesirable liquid-state water formationduring vapor flow through vapor flow circuit 314. Pressure andtemperature changes along vapor flow circuit 314 can affect whether thevapor is sustainable in a vapor state or condensed back into a liquid.Priming line 330 is provided to equalize temperatures and/or pressuresalong vapor flow circuit 314 in order to minimize or prevent undesirableliquid-state transition of the vapor during its progression throughvapor flow circuit 314. In one embodiment, an initial “purge” or“priming” procedure can be performed prior to delivery of a therapeuticvapor dose in order to preheat flow circuit 314 thus maintaining aconstant temperature and pressure in the main vapor flow circuit 314prior to delivery of a vapor to the target lung tissue.

As shown in FIG. 4, priming line 330 terminates at evaporator 332, whichis adapted to either house undesirable liquid in a collection unit (notshown) located within generator 300. In one embodiment, collection unitis adapted to house the liquid until a user or clinician is able toempty said collection unit. Alternatively, evaporator 332 is configuredto evaporate and expel said undesirable liquid into the ambient air.Baffle plates (not shown) or other like means can be incorporated inevaporator 332 to facilitate maximal vapor-to-liquid transition. Itshould be understood that other suitable evaporator configurations couldbe included to facilitate vapor-to-liquid transition during a primingprocedure of lines 314.

A number of sensors, operatively connected to a controller, can beincorporated into vapor generator 300, for example, in the liquidchamber, or along any point in vapor flow circuit 314. Water levelsensors, adapted to monitor the water level in the liquid chamber, canbe included. These water level sensors are configured as upper and lowersecurity sensors to sense or indicate when a liquid level in the fluidchamber is below or above a set fluid level. For example, if a waterlevel in the fluid chamber falls below the level of a lower watercontrol sensor, the controller can be configured to interrupt theoperation of the vapor generator 300.

In yet another embodiment, pressure sensors, or manometers, can beincluded in vaporizing unit 302, or at various points along the vaporflow circuit 314, to measure the liquid or vapor pressures at variousdiscrete locations and/or to measure vapor pressures within a definedsegment along circuit 314. One or more control valves 320 can also beinstalled at various points in the vapor flow circuit 314 to controlvapor flow, for instance, to control or increase the vapor flow or vaporflow rates in vapor flow circuit 314.

In yet another embodiment, a safety valve 322 can be incorporated intothe liquid chamber of vaporizing unit 302 and coupled to a vaporoverflow line 340 if the need for removing or venting vaporizing unit302 arises during generator 300 operation.

Although the vapor generator is described above having various specificfeatures, the components and configurations of the vapor generator andcatheter systems may vary. Additional vapor ablation systems aredescribed in, for example, U.S. Patent Publication No. 2015/0094607 toBarry et al., and U.S. Pat. No. 8,585,645 to Barry et al.; U.S. Pat. No.7,913,698 to Barry et al., and U.S. Pat. No. 8,322,335 to Barry et al.,and U.S. Pat. No. 7,993,323 to Barry et al.

In other embodiments, a condensable vapor is created in the handleportion of the catheter system. Consequently, a separate vapor generatorunit is not required. Systems including a resistive heater are describedin, for example, U.S. Patent Publication No. 2016/0220297 to Kroon etal. and U.S. Patent Publication No. 2014/0276713 to Hoey et al. Indeed,embodiments of the invention include a wide range of mechanisms tocreate and transport vapor through the working catheter as describedherein.

Vapor Ablation Catheter

FIG. 5 illustrates one embodiment of a user interface 360 of vaporgenerator 300. As illustrated, the user interface 360 comprises variousvisual readouts intended to provide clinical users information aboutvarious treatment parameters of interest, such as pressure, temperatureand/or duration of vapor delivery. Vapor generator 300 can also beadapted to incorporate one or more auditory alerts, in addition or inlieu of, visual indicators provided on user interface 360. These one ormore auditory alerts are designed to provide an alert to a clinicaluser, such as when vapor delivery is complete, when liquid chamber mustbe refilled or the like. As will be recognized by those in the art,other components, while not shown, can be incorporated including any ofthe following: a keyboard; a real-time imaging system display (such as aCT, fluoroscopy, ultrasound); memory system; and/or one or morerecording systems.

FIG. 6 illustrates yet another aspect of the invention, in particular avapor catheter 200 embodying various features of the present invention.Generally, catheter 200 is adapted to operatively connect to a controlhandle of vapor generator 300 via hub assembly 202. Catheter 200includes elongate shaft 204 defined by proximal section 206 and distalsection 208. Elongated shaft 204 is formed with at least one lumen (suchas a vapor, inflation, sensing, imaging, guide wire, vacuum lumen)extending from proximal section 206 to distal section 208 of shaft 204.Starting at proximal section 206, catheter 200 comprises strain reliefmember 201.

Elongated shaft 204 further comprises at least one occlusive member 210disposed at distal section 208 and distal tip 210 having at least onedistal port 212. In one embodiment, the at least one distal port 212 isconfigured as a vapor outlet port. In yet another embodiment, vaporoutlet port may also be used as an aspiration port while catheter iscoupled to a vacuum source (not shown) in order to aspirate mucus,fluids, and other debris from an airway through which catheter 200 isadvanced prior to vapor delivery. Alternatively, catheter 200 can beconfigured to include a separate vacuum lumen and aspiration ports asneeded. Distal tip 210 can be adapted into a variety of shapes dependingon the specific clinical need and application. For example, distal tip210 can be adapted to be atraumatic in order to minimize airway damageduring delivery.

The dimensions of the catheter are determined largely by the size airwaylumen through which the catheter must pass in order to deliver thecatheter to an airway location appropriate for treatment of the one ormore target tissues. An airway location appropriate for treatment of atarget lung tissue depends on the volume of the target tissue and theproximity of catheter tip to the target tissue. Generally, catheter 200is low profile to facilitate placement of catheter distal tip 210 asclose as practicable to proximally and peripherally located target lungtissue, i.e. in order to facilitate the catheter's advancement intosmaller and deeper airways. In addition, the low profile feature ofcatheter 200 also ensures that catheter can be delivered to the lungsand airways through a working channel of a bronchoscope, including forexample, through the working channels of ultra-thin bronchoscopes.Preferably, catheter 200 is slidably advanced and retracted from abronchoscope working channel. The overall length and diameter ofcatheter 200 can be varied and adapted according to: the specificclinical application; size of the airway to be navigated; and/or thelocation of the one or more target tissues.

Occlusive member or members 210 are similarly configured to provide thesmallest possible size when deflated to facilitate ready retraction ofcatheter 200 back into the working channel of a bronchoscope followingcompletion of a treatment procedure involving delivery of one or morevapor doses to one or more target tissues. The one or more occlusivemembers 210 are provided to obstruct of proximal vapor flow and/or seatcatheter 200 in the patient's airway during vapor delivery withoutslipping.

Obstruction of an airway by occlusive member 210 prevents retrogradeflow of vapor to tissues located outside of the desired target tissues.Because of the physiological characteristics of the airways, inparticular the fact that the airways ventilate and communicate specificlung parenchyma or tissues, vapor delivered or dispersed at a particularairway location (e.g. at the bronchial, sub segmental, main bronchi)determines whether there is a focal or regional heating of tissue. Inaddition to location of the catheter distal tip, other considerationsthat impact whether there is focal or regional tissue heating patterns(i.e. volume of tissue heated or size of thermal lesion) createdinclude: time or duration of vapor delivery; the vapor flow rate; andvapor content (dry vs. wet; vapor alone vs. vapor cocktail). Preferably,the one or more occlusive members 210 are compliant to ensure: adequateseating; airway obstruction; and/or complete collapse followingdeflation.

Catheter 200 can be fabricated from a variety of suitable materials andformed by any process such as extrusion, blow molding, or other methodswell known in the art. In general, catheter 200 and its variouscomponents are fabricated from materials that are relatively flexible(for advancement into tortuous airways) yet having good pushabilitycharacteristics and durable enough to withstanding the high temperaturesand pressures of the vapor delivered using catheter 200.

Catheter 200 and elongated shaft 204 can be a tubular braided polyimide,silicone, or reinforced silicone. These materials are relativelyflexible, yet have good pushability characteristics, while able towithstand the high temperature and pressures of vapor flow. Suitablematerials should be adapted to withstand vapor pressures of up to 80prig, at temperatures up to 170 degrees C. Specific suitable materialsinclude, for example, various braided polyimide tubing available, forexample, from IW High Performance Conductors, Inc. Similarly, the one ormore occlusive members 210 are preferably fabricated from similarmaterials having pressure and temperature tolerant attributes aselongated shaft 204, but preferably which is also compliant, such assilicone available from Dow Corning Q74720. As an added feature,catheter 200 and elongated shaft 204 can further be adapted to includevarying flexibility and stiffness characteristics along the length ofshaft 204 based on the clinical requirements and desired advantages.While not shown, various sensing members, including for examplepressure, temperature and flow sensors known in the art can beincorporated into catheter 200. For example, catheter 200 can be adaptedto include a sensing lumen for advancement or connection with varioussensory devices such as pressure, temperature and flow sensors.

Turing now to FIG. 7, illustrated is a preferred embodiment of a vaporcatheter 400. FIG. 7 is a longitudinal cross sectional view of theelongate shaft 404 while FIGS. 7A and 7B show transverse cross sectionalviews of the elongate shaft 404 taken along the lines 7A-7A and lines7B-7B respectively.

In this preferred embodiment, catheter 400 comprises an elongatedcatheter shaft 404 having an outer tubular member 406 and an innertubular member 408 disposed within outer tubular member 406. Innertubular member 408 defines a vapor lumen 410 adapted to receive a vaporand which is in fluid communication with a vapor flow circuit 314 ofgenerator 300. The coaxial relationship between outer tubular member 406and inner tubular member 408 defines annular inflation lumen 412. Vaporlumen 410 terminates at vapor port 424.

Inflation balloon 414 is disposed on a distal section of elongatedcatheter shaft 404 and having proximal 416 and distal 418 balloon endssealingly secured to outer tubular member 406. One or more inflationports 420 are disposed on outer tubular member 406 between the proximal416 and distal 418 ends of inflation balloon 414 so that the interior ofinflation balloon 414 is in fluid communication with inflation lumen412. (See FIG. 7B.)

As shown in FIG. 7, structural members 422 are disposed between innertubular member 408 and outer tubular member 406 at distal vapor port 424to seal inflation lumen 412 and provide structural integrity at thecatheter tip. Structural members 422 are preferably made of stainlesssteel, nickel titanium alloys, gold, gold plated materials or otherradiopaque materials, to provide catheter tip visibility underfluoroscopy and/or provide sufficient echogenicity so that the cathetertip is detectable using ultrasonography. Hub assembly 426 (or otheradaptor) at the proximal end of catheter 400 is configured to direct aninflation fluid (such as a liquid or air) into inflation lumen 412 aswell as provide access to vapor lumen 410.

FIG. 7B illustrates inflation balloon 414 in an inflated or expandedconfiguration. Inflation balloon 414 inflates to a cylindrical crosssection equal to that of a target airway in order to obstruct the airwayand prevent proximal or retrograde vapor flow. This inflatedconfiguration is achieved at an inflation pressure within the workingpressure range of balloon 414. Inflation balloon 414 has a workinglength, which is sufficiently long to provide adequate seating in atarget airway without slippage during or prior to vapor delivery.

Suitable dimensions for the vapor catheter 400 in accordance with thepresent invention include an outer tubular member 406 which has an outerdiameter of about 0.05 to about 0.16 inches, usually about 0.065 inchesand an inner diameter of about 0.04 to about 0.15 inches, usually about0.059 inches. The wall thickness of outer tubular member 406 and innertubular member 408 can vary from about 0.001 to about 0.005 inches,typically about 0.003 inches. The inner tubular member 408 typically hasan outer diameter of about 0.04 to about 0.15 inches, usually about0.054 inches and an inner diameter of about 0.03 to about 0.14 inches,usually about 0.048 inches.

The overall working length of catheter 400 may range from about 50 toabout 150 cm, typically about 110 to about 120 cm. Preferably, inflationballoon 414 has a total length about 5 to about 20 mm; a working lengthof about 1 to about 18 mm, preferably about 4 to about 8 mm. Inflationballoon 414 has an inflated working outer diameter of about 4 to about20 mm, preferably about 4 to about 8 mm within a working pressure rangeof inflation balloon 414. In preferred embodiment, outer tubular member406 and inner tubular member 408 is braided polyimide tubular memberfrom IWG High Performance Conductors. Specifically, the braidedpolyimide tubular member comprises braided stainless steel, with thebraid comprising rectangular or round stainless steel wires. Preferably,the braided stainless steel has about 90 picks per inch. The individualstainless steel strands may be coated with heat resistant polyimide andthen braided or otherwise formed into a tubular member or the stainlesssteel wires or strands may be braided or otherwise formed into a tubularproduct and the braided surfaces of the tubular product may be coatedwith a heat resistant polyimide.

As will be appreciated by those skilled in the art, the catheters andgenerators of the present invention can be used to heat one or moretarget lung tissue to treat a variety of lung diseases and conditions,including but not limited to: lung tumors, solitary pulmonary nodules,lung abscesses, tuberculosis, as well as a variety of other diseases anddisorders. In one embodiment, a procedure for inducing lung volumereduction (as a treatment for emphysema) involves advancing catheter 400into a segmental or sub-segmental airway and delivering a controlledvapor dose. As will be appreciated by those skilled in the art, thevapor carries most of the energy and heat required to convert liquid invapor generator from a liquid into a vapor. Upon dispersion of the vaporinto the airways, the vapor penetrates into the interstitial channelsbetween the cells, and distributes thermal area over a relatively largevolume of tissue, permitting tissue heating to be accomplished quickly,usually with a few seconds or minutes. Vapor heating of target lungtissue is intended to cause tissue injury, shrinkage and/or ablation, inorder to cause volumetric reduction of one or more target lung tissues.Lung volume reduction is immediate and/or occurs over several weeks ormonths.

Depending on the extent of the volumetric reduction (complete or partialreduction of a lobe) desired, catheter 400 is navigated into one or moreairways, preferably as into the segmental or sub-segmental airways andthe vapor delivered into as many airways as need during a singleprocedure to effect the therapeutically optimal extent of lung volumereduction. In a preferred embodiment, a vapor generator configured tocreate a vapor having a vapor pressure between about 5-50 prig, at atemperature between about 100-170 degrees Celsius. within vaporgenerator 300 is employed. The vapor catheter is delivered into thesub-segmental airways that communicate with either the left and rightupper lobes, and vapor delivered for a period of 1-20 seconds in each ofthese airways, to effect volumetric reduction of the left and rightupper lobes. Preferably, energy deliver to a target lung tissue isachieved without attendant plural heating sufficient to cause damage tothe pleura or a pneumothoraxes.

Vapor Ablation in Combination with LVR

In embodiments, thermal vapor ablation is combined with other lungvolume reduction treatment modalities. For example, and with referenceto FIG. 8, a modality to reduce the volume of the emphysematous tissue560 includes creating one or more openings 512 through the airway walls500 prior to delivering the condensable vapor. The surgically createdopenings 512 serve to release trapped air from the diseased tissue 560.

The openings 512 can optionally be maintained with conduits 600. Withoutintending to be bound by theory, the treatment of emphysematous tissueis improved by creating alternative airway passageways 512 for thetrapped gas to escape from the lung 518. The collateral channels 512provide new passageways for the air to escape, and reduce the volume ofthe diseased lung tissue, decrease hyperinflation and residual volume.

Exemplary catheters for making the openings include elongate flexiblecatheters comprising a piercing member or electrosurgical probe at thedistal end. An example of a piercing member 700 is shown in FIG. 12 andincludes a needle-like tip 710. An example of an electrosurgical probe720 is a monopolar RF ablation probe comprising an active electrode 722as shown in FIG. 13. A base or return electrode placed on the patient isnot shown. Alternately, bi polar or resistive-type ablation tips may beincorporated into the design to form the openings through the airwaywalls.

The openings may be enlarged with a dilator. Examples of dilatorsinclude inflation or expandable members as well as fixed taperedelongate shafts. An example of a dilator 730 having a taper 732 is shownin FIG. 14. A working lumen 734 may extend through the dilator such thatthe dilator may be advanced over the piercing member or otherwise guidedto the opening.

Exemplary techniques for identifying locations to create the openings,and for creating the openings are described in U.S. Pat. Nos. 6,692,494;7,393,330; 8,409,167; 9,421,070 and US Patent Publication No.2004/007315.

A challenge with treating emphysema by creating such openings, however,is to maintain the openings for a clinically significant time after thefirst procedure. If the openings are not maintained patent, and becomeoccluded, the lungs re-hyperinflate.

As described herein, embodiments of the invention address theabove-mentioned challenge by applying thermal vapor ablation to the lungtissue after the collateral channels have been created and in someembodiments, after the lung tissue is a reduced volume state. In asense, the thermal vapor ablation fixes or seals the lung tissue in thereduced volume state.

With reference to FIG. 9, a surgically created opening 612 is shown inan airway wall 630. A vapor delivery catheter is shown advanced alongthe airway lumen 630 to a location in the vicinity of the opening 612.Vapor is shown being delivered from the end of the catheter, and intothe lumen 630. The vapor flows along the airway, through the opening612, and to the diseased tissue 640. Additionally, a balloon 620 isshown deployed within the airway lumen to contain the vapor to thetargeted distal areas.

In another embodiment, and with reference to FIG. 10, a surgicallycreated opening is shown in the wall. A conduit 600 is deployed in theopening to maintain patency.

A vapor delivery catheter 506 is advanced through the opening 512 andbeyond the airway wall. Particularly, the end of the catheter is shownin the parenchymal tissue 560. The catheter is activated at this“shooting” position to disperse the vapor to the diseased tissue, beyondthe airway wall and to ablate the hyperinflated parenchymal tissue 560.

In another embodiment, and with reference to FIG. 11, a surgicallycreated opening 512 is initially created in the airway wall 550. Thelung tissue may initially decrease in volume to some degree as trappedair flows through the newly created opening.

Next, catheter 650 advanced into the opening 512. The catheter 650 isshown with a dual balloon 675, 680 type structure. The two balloons areaxially separated by a shaft portion 684 comprising an egress aperture686. The vapor delivery catheter is manipulated through the opening 550in a deflated state, and both balloons are inflated. The inflatedballoons isolate the surgically created opening 512. The ablationcatheter is then activated and delivers the vapor from the egressaperture 686 to the opening 512 only. The balloons 675,680 contain thevapor to the opening-only. Without intending to be bound by theory, itis anticipated that applying vapor to the airway opening only serves toseal the opening and prohibit the opening from premature closing.

The above described steps for delivering vapor to the tissue may becombined in any logical manner and the steps may be performed atmultiple locations and lung segments within the lung during the sameprocedure or in additional procedure and after a patient recoveryperiod.

In embodiments, the condensable vapor is delivered first, and then thecollateral openings are created through airway walls.

In embodiments, vapor is delivered only distally beyond the opening. Inother embodiments, the vapor is delivered only to the airway lumen afterthe holes have been surgically created. Still in other embodiments, thevapor is delivered and isolated to only to the surgically createdopenings.

In embodiments, multiple vapor ablations are performed within oneprocedure. For example, after one or more openings are created throughthe airway wall, the vapor is delivered into the openings. Then, thevapor delivery catheter is retracted to a new location proximal theopening, and the vapor is delivered to the lumen in fluid communicationwith the surgically created openings. Indeed, many combinations andvariations of the steps and timing are contemplated herein and areintended to all be within the scope of the invention except where suchcombinations are exclusive to one another.

Catheter Tracking and Guidance

As will be appreciated by one skilled in the art, various imagingtechniques (in addition to or in lieu of conventional bronchoscopicimaging) can be employed to assist with the medical interventionsdescribed herein. For example, real time fluoroscopy can be used toguide and confirm the position of vapor delivery catheter in the lung.Nonlimiting examples of guidance techniques include video or fluoroscopybased tracking and guidance, and/or electromagnetic based guidance viause of transponders or other sensors or transmitters. A wide variety ofsystems may be employed to track the location of the distal end of thecatheter and other instruments advanced into the lung and to compare orregister the location of the devices with previously obtained image dataof the patient. Examples of tracking and guidance techniques aredescribed in U.S. Pat. No. 7,233,820 to Gilboa; U.S. Pat. No. 7,756,563to Higgins et al.; U.S. Pat. No. 7,889,905 to Higgins et al.; U.S. Pat.No. 9,265,468 to Rai et al.; and U.S. Patent Publication No. 20160180529to Rai et al. See, e.g., the Superdimension™ Navigation System,manufactured by Medtronic (Minneapolis, Minn.), and the Archimedes™System, manufactured by Broncus Medical, Inc., (San Jose, Calif.).

Route Planning

Additionally, in embodiments, the physician can preoperatively plan oneor more routes through the airways to the target location to perform theprocedure described herein. An entire pathway or route may be plannedfrom the mouth or nasal passageway, through the airways, and to thetarget tissue whether within the lumen or outside of the lumen. Then,the pre-planned or pre-determined route may be used during the procedureto guide the physician. One of the above described guidance techniquescan be used to assess the location of the catheter as it is advancedinto the target position. Examples of a route planning techniques aredescribed in U.S. Pat. No. 9,037,215 and U.S. Patent Publication No.2009/0156895, both to Higgins et al. See also the LungPoint® Planner,manufactured by Broncus Medical, Inc., (San Jose, Calif.).

Alternative Embodiments

In embodiments, a staged procedure includes delivering vapor to one ormore segments of the lung, and observing whether the segment(s)clinically respond as desired to the vapor treatment. Should the segmentnot respond as desired, one or more surgically created openings can beformed in the offending lung segment. Then, a method includes deliveringa second dose of thermal condensable vapor through the surgicallycreated openings to the diseased lung segments that were unaffected bythe initial vapor treatment.

In another embodiment, a method for treating bulla includes creating oneor more openings leading to the bulla, and advancing the catheterthrough the openings. Once the position is confirmed, vapor is deliveredto the bulla to achieve the reduction of bulla.

In another embodiment, the method comprises applying vapor through theopenings-only for lung volume reduction and to preserve the mucociliarytransport system.

The invention has been discussed in terms of certain embodiments. One ofskill in the art, however, will recognize that various modifications maybe made without departing from the scope of the invention. For example,numerous variations, changes, and substitutions will now occur to thoseskilled in the art without departing from the invention. Moreover, whilecertain features may be shown or discussed in relation to a particularembodiment, such individual features may be used on the various otherembodiments of the invention.

1. A method for treating emphysema by reducing the volume of thediseased tissue in a lung of a patient, the method comprising:identifying a first lung segment leading to the diseased tissue, thelung segment comprising a first airway; creating at least one openingthrough a wall of the first airway; advancing a vapor delivery catheterinto the lung segment; and delivering an initial dose of condensablevapor from the vapor delivery catheter towards the diseased tissue; andwherein the step of delivering an initial dose of condensable vaporheats the diseased tissue causing the diseased tissue to be reduced involume.
 2. The method of claim 1 wherein the step of advancing the vapordelivery catheter into the first lung segment comprises advancing thevapor delivery catheter into the at least one opening.
 3. The method ofclaim 1 wherein the step of advancing the vapor delivery catheter intothe first lung segment comprises advancing the vapor delivery catheterthrough the opening such that the vapor delivery catheter is disposedoutside of the airway.
 4. The method of claim 1 wherein the step ofadvancing the vapor delivery catheter into the first lung segmentcomprises advancing the vapor delivery catheter along the first airwayto a position proximal to the at least one opening, and during thedelivery step, at least one a portion of the condensable vapor flowsalong the first airway towards the at least one opening and through theat least one opening to the diseased tissue.
 5. The method of claim 1wherein the step of creating an opening is performed with a deviceselected from the group consisting of a needle and a RF instrument. 6.The method of claim 1 further comprising delivering a second dose ofcondensable vapor to a second lung segment.
 7. The method of claim 6further comprising creating at least one opening through the wall of asecond airway in the second lung segment.
 8. The method of claim 1further comprising identifying at least one point along the first airwayfor creating the opening.
 9. The method of claim 1 further comprisingdelivering a second dose of vapor to the first airway and the at leastone opening.
 10. The method of claim 1 wherein the step of creating isperformed prior to the step of delivering.
 11. A method for treatingemphysema by reducing the volume of the diseased tissue in the lung of apatient, the lung comprising a plurality of airways, the methodcomprising: creating a plurality of collateral channels in the airwaysin the lung; and delivering a condensable vapor to the diseased tissue.12. The method of claim 11 wherein the creating a plurality ofcollateral channels comprises creating a plurality of openings throughairway walls.
 13. The method of claim 12 wherein the delivering acondensable vapor is performed subsequent to the creating step.
 14. Themethod of claim 13 wherein the creating and the delivering are performedwithin a first medical procedure.
 15. The method of claim 12 wherein thecreating is performed in a first procedure, and the delivering isperformed subsequent to the creating step in a second medical procedure.16. The method of claim 15 wherein the second medical procedure is atleast 8 weeks after the first medical procedure.
 17. The method of claim11 wherein the delivering is performed prior to the creating step. 18.The method of claim 11 wherein the delivering directs the condensablevapor to the airways.
 19. The method of claim 12 wherein the deliveringdirects the condensable vapor to the openings only.
 20. The method ofclaim 19 wherein the delivering a condensable vapor is performed with avapor delivery catheter comprising a double balloon.
 21. A method fortreating emphysema in a lung of a patient having a plurality of diseasedtissue segments comprising: creating a plurality of openings throughairway walls in a first diseased tissue segment; and deliveringcondensable vapor to a second diseased tissue segment.
 22. The method ofclaim 21 further comprising creating a plurality of openings throughairway walls in the second diseased tissue segment.
 23. The method ofclaim 22 wherein the delivering condensable vapor to a second diseasedtissue segment is subsequent to the creating a plurality of openingsthrough the airway walls in the second diseased tissue segment.
 24. Themethod of claim 21 further comprising delivering condensable vapor to afirst diseased tissue segment.
 25. The method of claim 24 wherein thesteps of delivering are performed with a vapor delivery cathetercomprising an inflatable balloon.
 26. The method of claim 21 wherein thestep of creating the openings are performed with a needle catheter. 27.A method for treating emphysema by reducing the volume of the diseasedtissue in the lung of a patient, the method comprising: advancing avapor delivery catheter along a first airway to a first position;delivering a dose of condensable vapor from the vapor delivery cathetertowards the diseased tissue; identifying candidate areas in the diseasedtissue of low clinical response to the delivering step wherein the stepof identifying is performed at least four (4) weeks subsequent to thestep of the delivering; creating at least one opening through an airwaywall in the vicinity of the candidate areas of diseased tissue; anddelivering a second dose of condensable vapor through the at least oneopening and towards the candidate areas of diseased tissue.
 28. Themethod of claim 27 wherein the step of identifying the candidate areasin the diseased tissue of low clinical response to the delivering stepis performed at least 8 weeks subsequent to the step of the delivering.